CVE-2026-89642

Summary

In the Linux kernel, the following vulnerability has been resolved:

cifs: call pagecache_isize_extended() in cifs_setsize() when extending

cifs_setsize() calls truncate_pagecache() but skips pagecache_isize_extended() on extension. truncate_setsize() shows the correct pattern:

i_size_write(inode, newsize); if (newsize > oldsize) pagecache_isize_extended(inode, oldsize, newsize); truncate_pagecache(inode, newsize);

pagecache_isize_extended() zeroes the tail of the page straddling old EOF. Without it, dirty bytes in that region can be written back to the server, exposing stale data in the newly extended range.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 12bafe32f09c0d24f5096154b59c347b9c6606e0affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c510edb9734af1c274d18f4f31a471a166bbc7e8affected
LinuxLinux2.6.12affected
LinuxLinux0 < 2.6.12unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References